Rio Tinto uncovers rare white diamond at famous Australian mine

Image: Rio Tinto Flikr

Western Australia’s iconic Argyle mine has produced one of the largest gem-quality white diamonds in its 35-year history, after Rio Tinto uncovered a 28.83 carat stone in March.

The diamond has been named Argyle Octavia for its unusual octahedral shape and could be the last major diamond yielded at the Argyle mine, which is set to shut down next year.

“We don’t see many this shape, or colour, or that clarity, generally out of the mine,” Argyle general manager of operations Andrew Wilson said. “We’ve probably seen 20 of those in the last 36 years of operations, of the plus 20 carat size.”

The Argyle mine is renowned as the world’s largest producer of coloured stones, particularly pink ones, with discoveries of larger white diamonds a much rarer occurrence.

“To find one that gets all the way through our crushers, and all the way through the sorting process, out to where we retrieve it … it’s quite unusual for it to be able to come out a fully formed diamond,” Wilson said.

Rio Tinto did not provide a price estimate for the diamond, but confirmed that it will be sold by tender at the world’s diamond trade capital, Antwerp.